The present invention relates to a fuel delivery device of a fuel tank for a vehicle, which supplies fuel to an engine.
Conventionally, a fuel delivery device of a fuel tank has controlled fuel supply to an engine from the fuel tank by opening/closing valve means so that especially when the fuel in the tank is decreased, air will not be delivered to the engine. Utilizing vertical movement of a float connected to the valve means, the valve means are opened/closed due to the relationship between negative pressure of a valve seat where the fuel is sucked and buoyancy of the float. More specifically, when the fuel tank contains sufficient fuel, the buoyancy of the float exceeds the negative pressure of the valve seat, and the float is detached from the valve seat. When the fuel in the tank is decreased, the negative pressure of the valve seat exceeds the buoyancy of the float, and the float is drawn and attached to the valve seat.
In order to operate the valve means reliably, vertical movement of the float should preferably be determined in one direction. Therefore, the float is usually surrounded by float guides so as to fix the direction of its vertical movement. By controlling a gap between the float and the float guides, the movement smoothness and the response speed of the float are determined.